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Patented Nov. l6, 11923. i

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1 entaunosn-n'rnna COMPOSITION.

To all whom it may concern:

Be it known that 1, JOHN M. Dononun,

' a citizen of the United States of America,

residing at Rochester, in the county of Monroe and State of New York, have in vented certain new and useful Improvements in Cellulose-Ether Compositions, of which the followingis a full, clear, and

, exact specification.

This invention relates to solvents for .makin strong'solutions of cellulose ether and a so relates to the cellulose ether compositions produced by theaid of such solvents. One object of my invention is to provide a solvent which will dissolve such large proportions of cellulose others that thick or viscous flowable solutions may h obtained for use in plastic and film making arts. Another object of my invention is to providea 'cellulose ether solution which may be manufactured into strong, flexible, transparent film on the. machines and by the methods now in use. Other objects will hereinafter appear. V.

In U. S. Patent, No. 1,188,3'7 6, Lilien-feld, June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are partically insoluble in water, and

my invention relates, but is not limited, to

the ethers having that; property. Whilev cellulose ethers form very thin solutions in the succinic acid esters of the lower monohydroxy aliphatic alcohols, such single solvents by themselves do not dissolve widely varying pro by using suitable common solvents, such as the lower monophydrbxy aliphatic alcohols. By the latter expressionli mean those havin less than 6 carbon atoms.

la the ingredients may be mixed in rtions, it is noted, by way of example, t at particularly useful compositionsv can be prepared by mixing equal parts by weight of the alkyl succinate with -the common solvent. Thus in the preferred form of my invention ll dissolve l part by weight of the cellulose ether, say

qualities, to the film may also be added to 0 Application area February 24, 1923. Serial No. 621,088.

water-insoluble ethyl cellulose in from 5 to 7 parts by wei ht of a solvent mixture comprising equa parts of ethyl succinate and methyl alcohol. The ingredients by themselves are not sufliciently powerful to make properly fiowable solutions of this strength. Of course, the proportion of mixed solvent or the proportion ,of the volatile ingredients, such as methyl alcohol, may be increased to adapt the composition to the lacquering art, as will be'understood by persons skilled therein.

Other substances which im art additional sup-pleness, or incombustibi ity, or other the dope, such, for instance, as triphenyl or tricr-esyl phosphate, monochlornaphthalene, camph'or,etc. The ingredients are of the ordinary commercial ty e andsufficiently purified for the process 0 film manufacture, so as to give a dope yielding films having the proper relative freedom from color. lhe viscous-flowable dope above described can be used in connection with the usual film-forming apparatus without the necessity of expensive alterations in the latter.

In the formation of a film by the spreading and drying ofthecompositions hereinabove described, a considerable amount of the alkyl succinate, such. as ethyl. succinate, remains behind, because of, the relatively low volatility of these compounds. They impart useful pla'stifying and" other properties to the film, which 1s normally flexible and transparent.

cellulose ether can be made much greater by-the use of rnymixed solvent. instead of using the succinate aloneas a solvent, it follows that a correspondingly greater procellulose ether dissolved in a mixture of a succinic acid ester of a lower mono-hydroxy aliphatic alcohol and a common solvent which brings out the latent solvent power 105 of the ester. v

2. A composition of matter comp-rising cellulose ether dissolved in a mixture of 7 methyl alcohol and ethyl succinate.

3. A flowable composition comprising 1 110 Since the ratio of the.

"weight of alkyl succinate to the weight of portion of alkyl succinate will present part of cellulose ether dissolved in from 5 to v 7 parts by weight of a. mixture of a lower monohydroxy aliphatic alcohol and asuccinic acid ester of a lower monohydroxy aliphatic alcohol.

LIA composition of matter comprising cellulose ether dissolved in a mixture of substantially equal parts by weight of a succinic acid ester of a lower monohydroxy aliphatic 7 alcohol and a common solvent which brings out the latent solvent power of the ester.

5. composition of matter comprising 1 part by weight of water-insoluble ethyl cellulose, 7 parts of ethyl suocinate and 7- parts of methyl alcohol. I c

6. As an article" of manufacture, a deposited, transparent', flexible film comprising .cellulose ether and fa succinate of a lower ether in said succinate alone.

Signed at Rochester, New York this 16th day of February, 1923.

i JOHN M. DONOHUE. 

